<template>
  <div class="todo-header">
    <input type="text" placeholder="请输入你的任务名称，按回车键确认" v-model="title" @keyup.enter="add"/>
  </div>
</template>

<script>
  import {nanoid} from 'nanoid'
  export default {
    name:'MyHeader', 
    data(){
      return {title:''}
    },
    methods: {
      add(e){
        // 数据校验
        if(!this.title.trim()) return alert('输入数据不能为空')
        // 将用户输入封装为 todo 对象
        const todo = {id:nanoid(), title:this.title, done:false}
        // console.log(todo) 
        this.$emit('addTodo', todo)
        // 清空输入框
        this.title = ''
      }
    },
  }
</script>

<style scoped>
  /*header*/
  .todo-header input {
    width: 560px;
    height: 28px;
    font-size: 14px;
    border: 1px solid #ccc;
    border-radius: 4px;
    padding: 4px 7px;
  }

  .todo-header input:focus {
    outline: none;
    border-color: rgba(82, 168, 236, 0.8);
    box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(82, 168, 236, 0.6);
  }
</style>